The present invention relates to a method for repairing a component, such as a turbine blade or a vane, used in a gas turbine engine.
Currently, gas turbine blade tips and trailing edge regions are repaired using a welding process such as gas tungsten arc welding without a backing material. The weld bead is used to build up cracked and worn surfaces. Problems occur when blade tip cracks expose blade internal cavities. In this case, the weld will flow into the cavity and result in a rejectable condition. In other areas, such as a blade trailing edge, weld repair will result in closure of the internal cooling features that will then need to be re-established by labor intensive blending or electrodischarge machining.
Accordingly, it is an object of the present invention to provide an improved method for repairing turbine engine components.
It is a further object of the present invention to provide a method as above which allows welding over open cavities and which does not require extensive post welding blend processing or machining.
It is yet another object of the present invention to provide a method as above which allows re-establishment of internal cooling geometry.
The foregoing objects are attained by the method of the present invention.
In accordance with the present invention, a method for repairing a component used in a turbine engine broadly comprises the steps of placing a piece of refractory metal material over an area of the component to be repaired and depositing a repair filler metal material over the piece of refractory metal material in an amount sufficient to repair the component and welding same. The refractory metal material may be any refractory material having a melting point in excess of 1455xc2x0 C. (2651xc2x0 F.) and may be coated or uncoated.
Other details of the repair method of the present invention, as well as other objects and advantages attendant thereto, are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.